Machine Tool

ABSTRACT

The invention relates to a CNC machine tool, especially a CNC lathe, comprising a horizontal main spindle. The unfinished parts to be machined are supplied to the machine tool horizontally to the working compartment by a handling device integrated into the CNC control, and are then supplied via the handling device to the chuck that is equipped with the horizontal main spindle. The machine tool according to the invention is especially suitable for small series machining.

The invention relates to a CNC-controlled machine tool, especially a CNC-controlled lathe.

PRIOR ART

Today, for loading and unloading machine tools, especially also of lathes, bar feeds with part catchers are also employed besides expensive portal loaders or robots. The portal loader or robot has to be newly adjusted upon each workpiece change. The bar feed is restricted by the passage (bore) and the spindle, and the removal of the finished parts is mostly effected through part catchers which cannot be employed with surface-sensitive workpieces.

From DE 33 29 266 A1, a CNC-controlled machine tool, especially a lathe, with horizontally operating main spindle is known, wherein a linearly movable gripper picks up workpieces from a conveyor and transports them into the processing region and from the processing region again to the conveyor.

DE 101 40 940 A1 describes a CNC-controlled machine tool, especially a lathe, with vertically operating main spindle, wherein workpieces are conveyed from a conveyor to a liftable delivering device by means of a delivering device, and are transported from there into the processing region and again back to the delivering device and from there to the conveyor by means of a linearly movable main spindle.

From U.S. Pat. No. 6,634,265 B2, a CNC-controlled machine tool, especially a lathe, with horizontally operating main spindle is known, wherein a linearly movable gripper tool unit picks up workpieces from a deposition surface and transports them into the processing region and from there again to the deposition surface.

OBJECT

The invention is based on the object to design a machine tool of the assumed kind such that it is still effectively employable with smallest series.

SOLUTION

The object is solved by a CNC-controlled machine tool according to claim 1 and according to claim 2.

SOME ADVANTAGES

The invention allows with simple and low-cost effort to convey workpieces, especially so-called bushing parts, even with smallest series into the processing space of a CNC machine tool, preferably a lathe. Here, the functionality of a CNC-controlled machine is included in order to allow a quick, flexible and low-cost solution of loading and unloading. Therein, considering standard components such as tool turrets and part catchers, minimizing the change-over times and the workpiece change times for automating the production is allowed, whereby also loading and unloading for smallest series becomes lucrative. Thus, for example, with the application of the teaching according to the invention it is possible to change over the loading and unloading means to new dimensions of workpieces to be processed, especially bushing parts, with few manual manipulations within shortest time, for example one minute.

For fast unloading, the normal workpiece catcher can be simultaneously be used for loading. If the workpieces should be treated gently due to the surface, thus, the reversal of the loading for removing workpieces is possible with low overhead (finished part pick-up in the turret) with low increase of the change time.

Thereby, the solution according to the invention is flexibly applicable upon customer demand.

Furthermore, no longer adjustment is given upon diameter changes. On supply, a small adjustment is required, since here only a prismatic stop has to be displaced and fixed, for example by means of winged screws. So called pressers formed as guide sheets do not have to be adapted upon diameter change. Gripper fingers are fast to be adjusted by means of adjusting screws. By the large stroke of the gripper especially formed as a pneumatic gripper, readjustment is only required upon change greater than 10 mm.

The gripper in the turret is pre-adjusted by means of a monkey wrench at a manual chuck and actuated by means of spring force.

Additionally, the invention is characterized in that the workpiece gripper is attached to swing arms (swing movements) and is linearly moved with a slider. By the mechanic coupling of the rotary and linear movements with only one motor, the dynamic flow can be effected from a rotary movement to a linear movement and vice versa without stopping. Thereby, the temporal flow is shortened and the component cost is greatly reduced.

Advantageously, the slider unit is universally employable. The delivery of the workpieces is effected horizontally into the working space and optionally out of this working space. The blanks are fetched vertically from a magazine and horizontally fed to the processing space of the machine tool, especially a lathe.

Optionally, a palette station can be provided. Unloading finished parts is effected to a linear or continuous conveyor, which can be formed as a belt conveyor or palette conveyor.

The workpiece length is automatically detected and evaluated by the torque regulation integrated in the CNC control. Adjustment upon workpiece length change is not required. This effects particularly advantageous in smallest series. If a number of workpieces, which are for example cylindrical on the outer side, are approached on a supply distance, this series of blanks has to be stopped, separated and fixed at a delivery position for taking measurements, thereby effecting isolation. The invention is characterized in that this is only effected by linear movement, for example by means of a cylinder driven by pressure medium pressure, preferably pneumatically, which is for example to be loaded alternatively on both sides by pressure medium pressure, especially pneumatically. Herein, the assembly of the isolation is chosen such that adjustment is not required upon change of the diameter. The pressing stroke to the workpiece gripper is chosen such that all of the workpiece lengths of the specification of the loading means proceed automatically without setup and adjustment. Thereby, quick change-over to new workpiece sizes is possible, and the employment of this loading means is also economical with small lot sizes.

FURTHER INVENTIVE DEVELOPMENTS

Inventive developments of the invention are described in the claims 2 to 21.

Further features result from the following description of the drawings, in which the invention is exemplified—partially schematically. There show:

FIG. 1 a machine tool formed as a CNC-controlled lathe in perspective view, wherein the handling device (9) is in the delivery position in the processing space;

FIG. 2 the lathe apparent from FIG. 1 in another perspective view, wherein the handling device (9) is in the take-over position at the magazine;

FIG. 3 a detail from FIGS. 1 and 2 in larger scale, also perspectively depicted;

FIG. 4 also a detail in the region of the slide table and the prism in larger scale, also perspectively depicted;

FIG. 5 a swing and rotating unit formed as a rotating and linear unit with the gripper swung downwards in perspective view;

FIG. 6 the rotating and linear unit apparent from FIG. 5 with the gripper swung in horizontal plane, perspectively exemplified;

FIG. 7 a cutout representation of the rotating and swing unit according to FIGS. 5 and 6 perspectively depicted, and

FIG. 8 a detail from FIGS. 1 and 2 in the region of the transporter in a schematic side view.

In the drawing, the invention is exemplified in application to a CNC-controlled lathe, which is substantially composed of a bench 1 and a slider unit 2 movable in a direction Y or Z and X or V by a motor, respectively, a turret 3 CNC-controlled and driven by a motor, including a turret disc 4.

The reference character 5 denotes a spindle box, while 6 represents a rack above which a gripper 7 formed as a pneumatic gripper is disposed. The gripper 7 is disposed liftable by a motor in opposite directions T and S, respectively, on two guide bars 8 with their longitudinal axes parallel to each other and extending horizontally. For this purpose, a rotating and linear unit 9 is associated with the gripper 7, which substantially has a planetary gearing 10, a drive motor 11 for example formed as a direct-current motor, a toothed belt pulley 12, a rotating unit 13, a transverse beam 14 for disposing the gripper 7. Through the drive motor 11 and the planetary gearing 12 and a not illustrated toothed belt, the rotating and linear unit 9 can be driven by a motor in the longitudinal axis direction of the guide bars 8, thus in the direction T and S, respectively, on the one hand, but the rotating unit 13 can also be swung in vertical plane, thus in the direction A and B, respectively, by more than 180°, preferably by an angle of 270°, according to which part is fixedly braked, on the other hand. For the lifting movement in T and S, respectively, for example, the toothed belt (not shown) guided over the toothed belt pulley 12 can be fixedly braked (be fixed), or the toothed belt pulley 12 is fixedly braked, thereby effecting a swing movement of the rotating unit 13 with the gripper 7 about the longitudinal axis of the planetary gearing 10 or the toothed belt pulley 12, respectively. In this manner, workpieces to be processed can be picked up and transported or processed workpieces can also be deposited again, if needed, respectively, in the manner described below.

The lathe apparent from the drawing has a working space 15, which can be encapsulated to the outside (not shown). Only a partition 16 can be recognized from the drawing, which has an opening 17, which is closable by a flap 18 swingably movable about a horizontal axis. The guide bars 8 are supported in the opening 17 such that the gripper 7 can transport gripped workpieces 19 through the opening 17 into the working space 15 and deliver them to a gripper 20 for example formed as a spring gripper, which delivers the picked-up workpiece 19 to the chuck 21 of a main spindle by a corresponding rotating movement and a displacement movement in the direction Y. The finished part is designated by the reference character 23. The main spindle is designated by 20.

A linear conveyor for example formed as a roller conveyor, which is driven by a motor or by gravity (e.g. chute), is designated by the reference character 24, by which the workpieces 19 to be processed (blanks) are conveyed. By the linear conveyor 24, the blanks 19 are fed to a supply device 25 described below in the direction C. At the end of the linear conveyor 24, a slide table 26 with horizontal supporting plate is provided, which has two plate- or sheet-shaped pressers 27, 28 diverging from each other in an angle α of 60° with the longitudinal axes in the illustrated embodiment, which are each disposed continuously slidable in the direction E, F or G, H, respectively, by a motor in longitudinal slots 29, 30 of the slide table 26, which are formed longer than these pressers 27, 28. The supply device 25 has a one-piece box-shaped formation, below the slide table 26 of which a transporter 31 is disposed liftable/swingable in the direction K and L, respectively. The transporter 31 is substantially composed of tongue-shaped transport tongues 34, 35, which are disposed in longitudinal slots 32 and 33, respectively, parallel and spaced from each other, roughened on its surface areas each protruding from the longitudinal slots 32 and 33 or provided with toothing or corrugation 36. The two transport tongues 34 and 35 and the pressers 27, 28 are driven in opposite directions by a lifting motor 37. This lifting motor 37 can be formed by a piston-cylinder unit to be loaded by pressure medium pressure, especially alternatively on both sides by pressurized air. At 38 and 39, two spaced, identical levers are disposed provided in pairs for each transport tongue 34 and 35. The lever pairs 38 and 39 and the not apparent lever pairs of the other transport tongue 34 or 35, respectively, are each drivable by a coulisse consisting of a continuous bolt 40 and 41 extending transversely to the lifting direction K-L and slot-shaped elongated holes 42 and 43, respectively, disposed in projections provided at the ends of the transport tongues 34 and 35, in which the bolts 40 and 41, respectively, migrate, if a lifting displacement in the direction K or L, respectively, is effected. Therein, the levers 38 and 39, respectively, swing about the axes 44 and 45, respectively, which are associated with the lifting motor 37, on the one hand, and about fixed axes 46 and 47, respectively, associated with the slide table 36, whereby the transport tongues 34 and 35 carry out a lifting displacement movement in the direction M or N (FIG. 8), respectively, and thereby lift blanks 19 situated on the slide table 26 and prevent them from a further forward movement in the direction C towards the pressers 27 and 28, respectively, or advance them between these diverging pressers 27 and 28. The axes 44, 45 are supported in elongated holes. Thereby, this part has three functions, namely a transport of the blanks 19, an isolation action and positioning with respect to the pressers 27 and 28, and a prism-like part 48, which is movable in the direction O and P, respectively, by a lifting motor 49 to be loaded alternatively on both sides by pressure medium pressure, especially by air pressure. The prism-like part 48 has corresponding to the angle that the pressers 27 and 28 form with their side wells facing each other, a corresponding recess 50, into which the workpieces 19 to be processed are inserted upon lowering the prism 48 and are then lifted off the slide table 26, whereupon they are gripped by the gripper 7 swung downwards in the direction A and then swung upwards by 270° and subsequently transported in the direction S to the working space 15 of the lathe, where they are delivered to the spring gripper 20, which delivers them in turn to the chuck 21 of the main spindle for processing. The movements of the pressers 27 and 28 are thus such that they press the blanks tangentially against the prism-like 48, while the longitudinal/lifting movement of the transport tongues 34, 35 of the transporter 31 is effected similarly to a sewing machine. Therein, the lifting stroke (tipping) over the lever mechanism 38, 39, 40, 41 (FIG. 8) of the transporter 31 is effected such that the transport tongues 34, 35 are lifted upon forward movement and are lowered upon rearward stroke. All of the drives as well as all of the lifting and swing movements can be included in a sequence control as well as largely in the CNC control of the lathe.

The torque monitoring allows to select and to start different NC processing 10 programs, respectively, after determining the part length. Thus, an automatic production of part families is possible. Tolerances can be defined for the workpiece lengths in order to ensure rejection/deposition without processing. Thereby, increase of the production safety results.

Horizontal supply of the blanks 19 into the working space 15 of the lathe occurs.

After complete processing, the chuck 21 is released such that the finished parts 23 drop or slide into a provided container via a chute or the like or can be transported away in other manner (not illustrated). However, also with surface-intensive parts it is possible to take the gripper 20 of the turret 3 for transporting off the completely processed workpieces 23, thus in turn delivering them to the gripper 7, which then transports the completely processed workpieces 23 in the direction T and conveys them in appropriate manner to the same 24 or another conveyer. This can occur by a linear or swing movement. It is possible to linearly move the rotary and linear unit 9 in the vertical position (gripper 7 directed downwards) in the direction S to deliver the finished part there to a conveyer disposed besides the feed 24. It is also possible to associate a further axis, for example a transverse axis, with the gripper 7 in order that the finished parts 23 can be conveyed on a parallel conveyor or in another manner to a conveyer disposed in an angle to the linear conveyer 24. The supply of blanks 19 on the one hand and the removal of finished parts 23 on the other hand are then fully-automatically effected.

The features described in the summary, in the claims and in the description as well as apparent from the drawing can be essential for the realization of the invention both individually and in any combinations.

REFERENCE CHARACTERS

-   1 Bench -   2 Slider unit -   3 Turret -   4 Turret disc -   5 Spindle box -   6 Rack -   7 Pneumatic gripper, gripper -   8 Guide bars -   9 Rotary and linear unit, handling device -   10 Planetary gearing -   11 Direct-current motor, drive motor -   12 Toothed belt pulley -   13 Rotary unit, handling device -   14 Transverse beam -   15 Working space -   16 Partition -   17 Opening -   18 Flap -   19 Workpiece, blank -   20 Spring gripper, gripper -   21 Chuck -   22 Main spindle -   23 Finished part -   24 Linear conveyor -   25 Feeding device -   26 Slide table -   27 Presser -   28 ″ -   29 Longitudinal slot -   30 ″ ″ -   31 Transporter -   32 Longitudinal slot -   33 ″ ″ -   34 Transport tongue -   25 ″ ″ -   36 Surface of the transport tongues 34, 35 -   37 Lifting motor -   38 Lever -   39 ″ -   40 Bolt -   41 ″ -   42 Elongated hole -   43 ″ -   44 Axis -   45 ″ -   46 ″ -   47 ″ -   48 Prism, prismatic part -   49 Lifting motor -   50 Recess -   A Swing movement of the rotary unit 13 -   B ″ ″ ″ ″ ″ ″ -   C Supply device of the blanks -   E Stroke of the presser 27 -   F ″ ″ ″ ″ -   G Stroke of the presser 28 -   H ″ ″ ″ ″ -   K Lifting/swing movement of the transporter 31 -   L ″ ″ ″ ″ ″ ″ -   M Lifting/displacement movement of the transport tongues -   N ″ ″ ″ ″ ″ ″ ″ -   O Stroke of the prism 48 -   P ″ ″ ″ ″ -   S Stroke of the gripper 7 -   T ″ ″ ″ ″ -   V Stroke of the slider unit 2 -   X ″ ″ ″ ″ ″ -   Y ″ ″ ″ ″ ″ -   Z ″ ″ ″ ″ ″ -   α Angle between the walls of the pressers 27, 28

LITERATURE REFERENCE

-   DE 33 29 266 A1 -   DE 101 40 940 A1 -   U.S. Pat. No. 6,634,265 B2 

1. CNC-controlled machine tool, especially a CNC-controlled lathe, including a horizontally disposed main spindle (22) with chuck (21), for receiving workpieces (19) to be processed, a handling device (3) disposed spaced from it and integrated in the CNC control for picking up and delivering blanks (19) to the chuck (21) of the main spindle (22) and for removing completely processed workpieces (23), a linear conveyor horizontally disposed parallel to the main spindle (22) and outside of the working space (15) and driven by a motor, at which a handling device (13) with gripper (7) driven by a motor is disposed guided in reciprocating (T-S) manner longitudinally displaceable, which takes over the workpieces (19) sequentially from a magazine, for example from a further linear conveyor (24), and conveys them into the working space (15) to the handling device (3) and delivers them to it and/or conveys completely processed workpieces (23) from the handling device (3) from the working space (15) again from the working space (15), wherein for transport and for isolation of the approached blanks (19) and for alignment thereof with respect to the delivery position to the gripper (7) of the handling device (13) towards the arriving blanks, pressers (27, 28) diverging from each other and each longitudinally displaceable (E, F, G, H) by a limited amount in their longitudinal axis direction are associated with the magazine or the like (24), with which the concerned blank (19) can be pressed up to the delivery position, wherein the following blanks (19) are further transportable.
 2. CNC-controlled machine tool, especially a CNC-controlled lathe, including a horizontally disposed main spindle (22) with chuck (21), for receiving workpieces (19) to be processed, a handling device (3) disposed spaced from it and integrated in the CNC control for picking up and delivering blanks (19) to the chuck (21) of the main spindle (22) and for removing completely processed workpieces (23), a linear conveyor horizontally disposed parallel to the main spindle (22) and outside of the working space (15) and driven by a motor, at which a handling device (13) with gripper (7) driven by a motor is disposed guided in reciprocating (T-S) manner longitudinally displaceable, which takes over the workpieces (19) sequentially from a magazine, for example from a further linear conveyor (24), and conveys them into the working space (15) to the handling device (3) and delivers them to it and/or conveys completely processed workpieces (23) from the handling device (3) from the working space (15) again from the working space (15), wherein a torque regulation integrated in the NC control is associated with the handling device (3) in the working space (15), by which the dimensions of the blanks (19) each delivered to the handling device (3) can be automatically detected and by which the dimensions can be evaluated within preset tolerances.
 3. Machine tool according to claim 1, characterized in that the longitudinal axes of the pressers (27, 28) form an angle (α) of less than 90°, preferably ≦60°, with each other.
 4. Machine tool according to claim 1, characterized in that the pressers (27, 28) are guided in liftable manner by a motor in their longitudinal axis direction in longitudinal slots (29, 30) of a slide table (26) and are lockable in the respective position.
 5. Machine tool according to claim 1, characterized in that the side walls of the pressers (27, 28) facing each other contact the respective blank (19) tangentially in the manner of circle tangents such that the straight line orthogonally standing on a circle tangent in the point of contact passes through the center of circle of the round blank (19) such that adjustment of the isolation is not required upon diameter variation of the workpieces (19).
 6. Machine tool according to claim 1, characterized in that that pressers (27, 28) are associated with a slide table (26) formed as a delivery table, which has a lifter driven in opposite directions in the vertical direction (P-O) on its rear side, which has a kind of prism (48), by which the blanks (19) centered between the pressers (27, 28) are detected and lifted vertically to the gripper (7) of the handling device (13) into a delivery position.
 7. Machine tool according to claim 1, characterized in that at least one horizontal rigid guide (8) with its longitudinal axis extending parallel to the main spindle (22) is disposed outside of the working space (15), at which the handling device (13) is disposed outside of the working space (15) with its gripper (7) longitudinally displaceable by a motor in at least one plane (T-S) in opposite directions and/or rotatable and/or swingable (A-B), and that the motor drive of the handling device (13) is controlled in position.
 8. Machine tool according to claim 1, characterized in that the working space (15) is closed by an openable partition (16) on one side, through which the gripper (7) of the handling device (13) forcedly guided outside of the working space (15) can be moved for the purpose of delivery to the handling device (3) disposed in the working space (15).
 9. Machine tool according to claim 1, characterized in that the handling device (3) disposed in the working space (15) is a multi-turret, which is drivable by a motor about an axis disposed parallel to the rotating axis of the main spindle (22), wherein the motor drive is integrated in the CNC control.
 10. Machine tool according to claim 1, characterized in that the handling device (13) of the linear conveyor, formed as a rotary and linear unit, is drivable by one and the same motor (11) in opposite directions (T-S) and is also swingable (A-B) by more than 180°, preferably by 270°.
 11. Machine tool according to claim 2, characterized in that the turret (3) liftable parallel to the main spindle (22) is movable with a reduced torque into the delivery position, and after reaching the torque, the workpiece length is detectable and evaluatable within preset tolerances, and the concerned blank (19) can be deposited in replacement upon measurement results outside of these tolerances, otherwise can be delivered to the chuck (21) of the main spindle (22) for processing, and subsequently the selection of the NC processing program can be started according to the workpiece length.
 12. Machine tool according to claim 6, characterized in that the prism (48) is displaceable and fixable by means of winged screws.
 13. Machine tool according to claim 6, characterized in that the lifting movement of the pressers (27, 28) effects lifting of transport tongues (34, 35) at the same time and transports the following workpieces (19) further by the longitudinal stroke.
 14. Machine tool according to claim 6, characterized in that the lifting movements of the pressers (27, 28) and of the prism (48) as well as of the grippers (7) can be monitored via end position switches or the like such that missing of workpieces (19) can be detected in the corresponding flow and results in alarm message (process safety).
 15. Machine tool according to claim 13, characterized in that a roughening, corrugation or toothing increasing the frictional connection is associated with the transport tongues (34, 35) on their upper sides facing the blanks (19).
 16. Machine tool according to claim 13, characterized in that the transport tongues (34, 35) are driven in liftable/swingable manner (N-M) via a coulisse guide and via a parallelogram lever drive with a lifting motor (37) disposed below the slide table (26).
 17. Machine tool according to claim 16, characterized in that the transport tongues (34, 35) each have two spaced projections with longitudinal slots disposed at their ends, with which bolts (40, 41) are engaged, which are driven via spaced levers (38, 39) of the parallelogram gearing upon lifting movement (K-L) of the lifting motor (37).
 18. Machine tool according to claim 16, characterized in that the movement of the pressers (27, 28) on the one hand and that of the transport tongues (35, 35) on the other hand are matched to each other and that the pressers (27, 28) and the transport tongues (34, 35) can be driven by one and the same lifting motor (37).
 19. Machine tool according to claim 6, characterized in that the linear conveyor (24) conveying the blanks (19) conveys the blanks (19) onto the slide table (26) disposed below the swing plane of the rotary unit (13).
 20. Machine tool according to claim 16, characterized in that the slide table (26) represents the surface of a box-shaped part of the supply device (25), which receives the lifting motor (37) for driving the transport tongues (34 and 35) on the one hand, but also for driving the pressers (27, 28), and which has longitudinal slots (29, 30) for guiding the pressers (27, 28).
 21. Machine tool according to claim 6, characterized in that the liftable prismatic part (48) with lifting motor (49) is disposed on the side of the slide table (26) facing away from the linear conveyor (24) for conveying the blanks (19). 